Sensitivity analysis studies the relationship between the output of a model and its input variables or assumptions. Historically, the need for a role of sensitivity analysis in modelling, and many applications of sensitivity analysis have originated from environmental science and ecology. [1]
Hydrology and water quality are two modelling fields where sensitivity analysis was applied quite early. Relevant examples are the work of Bruce Beck, [2] George M. Hornberger, [3] Keith Beven [4] and Robert C. Spear. [5]
More recent applications encompass snow avalanche models, [6] land depletion, [7] marine biogeochemical modelling, [8] irrigation [9] and again hydrological modelling. [10]
Several methods related sensitivity analysis have been developed in the context of environmental applications, such as Data Based Mechanistic Model due to Peter Young [11] and VARS due to S. Razavi and H. V.Gupta. [12] [13] [14]
In a 2019 work on the take-up of sensitivity analysis in different disciplines, among 19 different subject areas, environmental sciences were found to have the highest number of papers, which become even higher if the papers in earth sciences are included. [15]
Reference journals for applications of sensitivity analysis in environmental science are Environmental Modelling & Software , Water Resources Research , Water Research , Ecological indicators [16] and others.
Sensitivity analysis is part of recent checklists or guidelines for environmental modelling. [17] [18] [19] [20]
A Special Issue on Sensitivity analysis for environmental modelling in preparation. [21]
Hydrology is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is called a hydrologist. Hydrologists are scientists studying earth or environmental science, civil or environmental engineering, and physical geography. Using various analytical methods and scientific techniques, they collect and analyze data to help solve water related problems such as environmental preservation, natural disasters, and water management.
Sensitivity analysis is the study of how the uncertainty in the output of a mathematical model or system can be divided and allocated to different sources of uncertainty in its inputs. A related practice is uncertainty analysis, which has a greater focus on uncertainty quantification and propagation of uncertainty; ideally, uncertainty and sensitivity analysis should be run in tandem.
Equifinality is the principle that in open systems a given end state can be reached by many potential means. The term and concept is due to the German Hans Driesch, the developmental biologist, later applied by the Austrian Ludwig von Bertalanffy, the founder of general systems theory, and by William T. Powers, the founder of perceptual control theory. Driesch and von Bertalanffy prefer this term, in contrast to "goal", in describing complex systems' similar or convergent behavior. Powers simply emphasised the flexibility of response, since it emphasizes that the same end state may be achieved via many different paths or trajectories.
The Nash–Sutcliffe model efficiency coefficient (NSE) is used to assess the predictive skill of hydrological models. It is defined as:
The HBV hydrology model, or Hydrologiska Byråns Vattenbalansavdelning model, is a computer simulation used to analyze river discharge and water pollution. Developed originally for use in Scandinavia, this hydrological transport model has also been applied in a large number of catchments on most continents.
Generalized likelihood uncertainty estimation (GLUE) is a statistical method used in hydrology for quantifying the uncertainty of model predictions. The method was introduced by Keith Beven and Andrew Binley in 1992. The basic idea of GLUE is that given our inability to represent exactly in a mathematical model how nature works, there will always be several different models that mimic equally well an observed natural process. Such equally acceptable or behavioral models are therefore called equifinal.
A runoff models or rainfall-runoff model describes how rainfall is converted into runoff in a drainage basin. More precisely, it produces a surface runoff hydrograph in response to a rainfall event, represented by and input as a hyetograph. Rainfall-runoff models need to be calibrated before they can be used.
A hydrologic model is a simplification of a real-world system that aids in understanding, predicting, and managing water resources. Both the flow and quality of water are commonly studied using hydrologic models.
Robust decision-making (RDM) is an iterative decision analytics framework that aims to help identify potential robust strategies, characterize the vulnerabilities of such strategies, and evaluate the tradeoffs among them. RDM focuses on informing decisions under conditions of what is called "deep uncertainty", that is, conditions where the parties to a decision do not know or do not agree on the system models relating actions to consequences or the prior probability distributions for the key input parameters to those models.
OptiY is a design environment software that provides modern optimization strategies and state of the art probabilistic algorithms for uncertainty, reliability, robustness, sensitivity analysis, data-mining and meta-modeling.
In statistics, robust Bayesian analysis, also called Bayesian sensitivity analysis, is a type of sensitivity analysis applied to the outcome from Bayesian inference or Bayesian optimal decisions.
Analytica is a visual software developed by Lumina Decision Systems for creating, analyzing and communicating quantitative decision models. It combines hierarchical influence diagrams for visual creation and view of models, intelligent arrays for working with multidimensional data, Monte Carlo simulation for analyzing risk and uncertainty, and optimization, including linear and nonlinear programming. Its design is based on ideas from the field of decision analysis. As a computer language, it combines a declarative (non-procedural) structure for referential transparency, array abstraction, and automatic dependency maintenance for efficient sequencing of computation.
P-boxes and probability bounds analysis have been used in many applications spanning many disciplines in engineering and environmental science, including:
Modelling frameworks are used in modelling and simulation and can consist of a software infrastructure to develop and run mathematical models. They have provided a substantial step forward in the area of biophysical modelling with respect to monolithic implementations. The separation of algorithms from data, the reusability of I/O procedures and integration services, and the isolation of modelling solutions in discrete units has brought a solid advantage in the development of simulation systems. Modelling frameworks for agriculture have evolved over time, with different approaches and targets
Keith John Beven is a British hydrologist and distinguished emeritus professor in hydrology at Lancaster University. According to Lancaster University he is the most highly cited hydrologist.
Silvio O. Funtowicz is a philosopher of science active in the field of science and technology studies. He created the NUSAP, a notational system for characterising uncertainty and quality in quantitative expressions, and together with Jerome R. Ravetz he introduced the concept of post-normal science. He is currently a guest researcher at the Centre for the Study of the Sciences and the Humanities (SVT), University of Bergen (Norway).
Shirley Jean Dreiss (1949–1993) was an American scientist working in the fields of hydrology and hydrogeology. After gaining her PhD from Stanford University, she joined the faculty of the University of California at Santa Cruz, where she became Professor and Chair of the Department of Earth Sciences. She made important contributions to the understanding of water flow through karst aquifers and fluid flow in subduction zones. At the time of her early death in a car accident, she was studying the groundwater system of Mono Lake in California. She was awarded the Birdsall Distinguished Lectureship from the Geological Society of America, which was renamed the Birdsall-Dreiss Distinguished Lectureship after her death.
Sensitivity analysis studies the relation between the uncertainty in a model-based the inference and the uncertainties in the model assumptions. Sensitivity analysis can play an important role in epidemiology, for example in assessing the influence of the unmeasured confounding on the causal conclusions of a study. It is also important in all mathematical modelling studies of epidemics.
Andrea Saltelli is an Italian scholar studying quantification with statistical and sociological tools, extending the theory of sensitivity analysis to sensitivity auditing.
Ezio Todini is an Italian academic, hydrologist and civil engineer.